1. Field of the Invention
The present invention relates to a seatback frame for vehicles, which is constructed such that a lower cross member couples both sides of a lower end of a back frame, to which a recliner hinge shaft is hinged, to each other.
2. Description of Related Art
Typically, a vehicle seat includes a seat frame and a back frame. The seat frame supports the lower part of a passenger's body when the passenger is seated. The back frame is coupled to the seat frame in such a way as to tilt forward and backward, and support the upper part of the passenger's body.
As shown in FIGS. 1 and 2, a conventional back frame 20 generally is pivotally coupled to a seat frame via a recliner hinge shaft 30, as seen in detail 1A of FIG. 1. Referring to detail 1B of FIG. 1, a lower cross member 10 is provided on the lower portion of the back frame 20, and connects both sides of the back frame 20 to each other to support the back frame 20.
A back pad 40 is provided on the back frame 20 to allow a passenger to comfortably sit in the seat. In order to prevent the back pad 40 and the recliner hinge shaft 30 from interfering with each other when the back frame 20 tilts, the outer portion of the recliner hinge shaft 30 is surrounded with a tube 50.
However, because the conventional lower cross member 10 usually has an “I”-shaped cross section, the lateral strength of the lower cross member 10 is low. Thus, it is difficult for the lower cross member 10 to satisfy regulations regarding the strain requirements thereof.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.